Secondary galvanic battery.



H. P. R. L. PRSCKE & J. A. E. ACHBNBAGH.

SECONDARY GALVANIO BATTERY. APPLIOATION FILED APR.22, 1911.

1,1 1 9,31 3, Patented Dec.1,1914.

HEINRICH PAUL RUDOLF LUDWIG PRSCKE AND JULIUS ADOLPH ERWIN ACHENBACH, OF HAMBURG, GERMANY.

SECONDARY GALVANIG BATTERY.

Application ied April 22, 1911.

To all whom it may concern:

Be it known that we, HEIN RICH PAUL RU- DOLF LUDWIG Pasokn and JULIUS ADOLPH ERWIN ACHENBAGH, subjects of the German Emperor, residing at Hamburg, in' Germany, have invented certain new and useful Improvements in Secondary Galvanic Batteries, of which the following is a specification. f

The akaline accumulators proposed by Edison and J ungner contain, as active substances, nickel or cobalt oxid compounds for the positive, and iron oXid compounds for the negative electrodes, The initial material employed for the positive electrodes is generally green oxyhydrate of nickel, while that for the negative electrodes is generally ferrous oXid of iron. Both these materialsare' known to be poor conductors of electricity. Edison and Jungner have therefore been led to add suitable conductive means such as graphite or shavings of nickel..

These inert additions necessarily increase the weight very considerably. It may be taken that on an average the positive electrodes' containapproximately 50% by weight of active conductive material and 50% of inert conductive material. The mixture has been inclosed under high pressure inperforated conductive metal pockets, it having hitherto been found impossible to form a solid mass of the powdered active material. The weight of the metal pockets containing the active substance, a's well as that ofthe metal supports carryin the pockets further increase the weight o the electrodes very considerably. A positive electrode of this description contains roughly, assummg the total weight to be 100 grams, 25 `gramsof oxyhydrate of nickel, 25 grams of inactive conducting additions and 50 grams of supporting and pocket material. The `active material in these accumulators is only very incompletely utilized. Furthermore, in tune the active substance passes through the perforations in the metal pockets into the electrolyte, which results 1n the contact being broken between the-active material and the conducting substance.

The object of the present invention is to remove these disadvantages and to enable all the components to be utilized as fully as possible, with aview to lowering the weight with respect alkaline accumulatore.

Specification of Letters Patent.

to the watt-hour capacity of Patented Dec. 1, 1914.

Serial No. 622,644.

The invention is illustrated in the accompanying drawing, in wl1ich:-

Figure 1 is a perspective elevation of a partly prepared electrode, Fig. 2 a similar view of the finished electrode, Fig. 3 a sideview of a series of electrodes placed together for battery work, and Fig. 4 a side-view showing said electrodes joined to a conductive frame.

For the purpose of our invention we make the poorly-conductive active compounds, in the form of a fine and non-coherent powder, into a stti1 paste, after moistening them with water or alkaline or other suitable solutions, and then paste them into a piece of woven fabric or gauze made of nickel or other suitable metal. The metal fabric must be very tine, the meshes being usually less than 0:1 mm. in width. Ve have found by experience that metal gauze having 1:30-2:30 meshes per square cm. is suitable. In the accompanying drawing, a represents a piece of fabric of this kind, the size of the meshes being, however, greatly exaggerated. lThe gauze is preferably so pasted with the mass that only the meshes are filled with small scales b of active mass, so that the thickness is not increased by a coating of the substanceon the surface. Before pasting, the metal gauze 'is preferably provided with a terminal conductor c in the form of a wire or strip or a small tube, which ma be electrically welded along one edge o the gauze. The pasted metal gauze may then berolled tightly around the terminal conductor'and with a view to obtaining perfect coherence between the active substance and the sup-` port thereof the cylindrical body may then be rolled upon a suitable metal or glass plate, or may be pressed in a mold.

Nickel wire d, preferably thin, may be wound around theelectrode, and have its ends attached to the terminal conductor. Vf is a supporting sleeve which may be of cotton spun on directly, of cloth tied or sewed in place, or the like. The inclosing of the electrode with chemically indifferent and non-conducting material' revents the pu1- verulent `substance from p eing washed out of the fine pores of the outer layer, but is not essential to the invention.

Owing to the extreme distribution of the poorlylconducting active substance in the finely `meslied metal gauze, it is not necessary to mix `an inactive conducting material with.the active mass. ylhe function of the inactive conducting medium is performed by the metal gauze, which serves as an extremely light and satisfactory conducting support with a large superficial area, and 'occupies very little space when rolled up. By rolling `up the metal gauze tightly into a rod, firm and certain contact is insured between the active paste and the gauze, the layers of gauze placed one upon the other render it impossible for the substance to be washed out, thou 'h the electrolyte has suflicient diffusion. n electrode thus produced is not injuriously affected by gas pressure or changes of volume of the active material, during charging and discharging, the contact remaining perfect. The electrode also resists the action of vibration and mechanical influences.

A plurality of the above described roller shaped electrodes may be combined to form azcomposite electrode for a battery by placing them in a supporting frame e made of suitable material, preferably nickel, without any, or with very little, space between them. rfhe electrodes are secured to the frame by the two ends of the terminal wires, rods, tubes or the like c projecting centrally from 4 either end of the electrodes, these terminals -tecting insulating and supporting envelop about the :lrameworlr.A

andere 2. A cathode, for use in alkaline galvanic secondary batteries, composed of a porous metallic framework inactive in the alkaline solution, a mass of pulverulent, non-coherent, poorly conductive active material, containing an oXid of the metal of the framework and supported and rendered more conductive by said framework, an exterior protecting and insulating sleeve, and terminals attached to said framework.

3. A cathode, for use in alkaline galvanic secondary batteries, composed of a porous metallic framework of nickel inactive in the alkaline solution, a mass of pulverulent, non-coherent, poorly conductive active material of nickel hydroxid supported and rendered more conductive by said framework, terminals projecting from said framework, and an enveloping projecting and retaining sleeve of non-conductive material around said framework.

il. A cathode, for use in alkaline galvanic secondary batteries, composed of a porous metalllc framework of nickel gauze inactive' in the alkaline solution, a mass of vpulverulent, poorly conductive, non-coherent active material of nickel hydroXid supported in the interstices of said framework, a terminal rod soldered to and tightly wrapped in said framework, said terminal rod being inactive in the alkaline solution and projecting from the body of the electrode, andan enveloping, protecting and retaining sleeve of nonconductive material about the .framework and the active material therein.

ln witness whereof we have signed this specication in the presence of two witnesses.

HEINRICH PAUL RUDOLF LUDWIG PRSCKE. JULlUS ADLPH ERWlN CHENBACH. Witnesses:

ERNEST H. L. Muraiunnnorr, Eemian Horn.. 

